empty try block

[chetana kumar]

what happens when you have a try block without any code folloewd by a catch block that catches some exception?

[Surendra Kumar]

You can have that, provided that the exception is some unchecked exception.

[Brian Mozhdehi]

Nothing happens. The catch block will only catch an exception thrown in the Try block. If nothing happens in the try block, then no exception could ever possibly be thrown and therefore whatever is in the catch block would never be executed.

It wont throw a compiler issue, i.e. it will compile. But its pointless to add such a thing to any application.

[Stary Kapec]

You can have that, provided that the exception is some unchecked exception.

    
    public static void main(String[] args) {
        try {
        } catch (NullPointerException e) {
        } catch (Exception e) {            
        } catch (Throwable t) {            
        }
    }

e and t exceptions are also allowed. Are they also considered as checked exceptions?

[Naseem Khan]

Those classes which extend Exception is checked only with the exception of java.lang.RuntimeException class.

Al other is unchecked. e.g., Throwable, Error, Exception all are unchecked.

Naseem

[Barry Gaunt]

It wont throw a compiler issue, i.e. it will compile.

Wrong. This code produces a compiler error:

public class DontThrowUp
{
    public static void main(String[] args) {
        try {
        } catch (InterruptedException e) {
        }
    }
}

[Henry Wong]

e and t exceptions are also allowed. Are they also considered as checked exceptions?

The compiler will not complain about any unchecked exception -- or any throwable class that an unchecked exception is an instance of. There are unchecked exceptions that are instance of the Exception and Throwable classes, hence, it will not complain.

Henry

[Stary Kapec]

Throwable, Error, Exception all are unchecked.

    
    static void foo() throws Exception {}
    
    public static void main(String[] args) {
        foo(); // compiler error
    }

But even though Exception is not checked, compiler still requires it to be checked :-) So why not to call it checked? The same is true for Throwable.

[Naseem Khan]

How the compiler will know which exception object is thrown from foo() method. It could be an instance of IOException which is checked so compiler will force you to catch it or declare it by throws clause.

Naseem